A small stepper for a man...

andrea-i

28 Sep 2018, 15:07

Hi all! After a long time trying to sort out life matters in order to have the space and the time to dedicate to this project, it's finally on!

My cheapo CNC machine has finally behaved itself and I've managed to send the right orders from the cad app to make my first successful switch hole (yes, it was way more complex than just push button -> print).
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Cheap CNC apparently also means poor support from cad software, so I had to actually learn G-Code and modify the translator to run the right instructions during milling.

Next up is making a full plate out of that beautiful paulownia wood, too bad the plate is twice as long as the supported volume for my cnc, so there's gonna be some more trial and error...

If this is interesting to someone, anyone, then I'll probably keep this thread running with my attempts at making a whole custom keyboard.

Kurplop

28 Sep 2018, 20:34

I’m interested. I’d like to see regular progress reports.

andrea-i

02 Oct 2018, 10:12

Some tales of horror from CNC land...

Last sunday I made the most significant progress with my crappy CNC, I had an issue where the vertical motor was skipping some operations, eventually nailed it down to this little thing here called the motor's driver:
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Each stepper motor has one of these and if they heat up too much it will stop working for a bit.
Turns out that little screw in the picture is used as a potentiometer to regulate how much current goes from the driver to the motor, after regulating it all went fine and I was finally able to print.

Finding and solving this issue was hell! imagine a whole sunday spent testing all possible scenarios when all you wanted was to machine your damn switch plate!

All part of the process I guess, but I should be close to be able to machine a whole plate no matter the size.
Finding the right size for the sketches took some attempts, putting just the right size of the switch in the cad software wasn't good enough, they came out very loose.
Eventually I've found the right measure to have a very firm mount for any mx compatible switch.
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Oh, because of the grainy wood I guess, I did not need to level down the switch clipping area to 1.5mm thickness, it just fits on 4mm wood and stays there firmly.

I'll probably do another post on how I can subdivide jobs for the cnc to machine a plate that is bigger than the supported print area.

I would have shown a full plate today but...the computer went to sleep and the machine stopped, so I'll have to re-prepare a piece of wood to start the machining all over again, the thing is laud as f*, so if I want to have both my cnc and my girlfriend in the same house I have to patiently wait for the right time to turn the thing on ; )
Probably this weekend I will have my first plate, finally!

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Muirium
µ

02 Oct 2018, 10:28

Yes, I’d particularly like to know how you pull a big rabbit out of the that little hat. Saw the bunny in half?

andrea-i

02 Oct 2018, 10:56

**no rabbits were harmed during the fabrication of this keyboard**

The way the machine works is by telling it before each job where is the start point.
It goes like this:
1) I manually position the router in an approximated start position.
2) I hit start and the machine will start from that point.
3) in the cad app I make sure that before to end the first half of the plate it will leave a little mark on it.
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4) Once job #1 is done, I move the wooden plate forward on the cnc and I re-center the router onto the little mark left from job #1.
5) hit start and continue with job #2.

This way I can machine a plate that is bigger than my cnc, which, when I bought this piece of crap, was my main concern.

There's still a lot that could go wrong, like hinges loosing up during the jobs, but I'm working on that too to reinforce the cnc structure.

Btw, this is the machine I'm using:
https://reprap.org/wiki/MaduixaCNC

It's not as bad as I make it to be, but surely not the best tool for the job. MDF structure with 3d printed hinges, you can't really expect to machine aluminium with that thing out of the box.

andrea-i

07 Oct 2018, 12:27

It took another few attempts, but I can now make my own wooden plates fairly quickly : )
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I'm already working on the case, I'll keep working on 4mm sheets of wood, I like the DIY kit feel of this project. Taking the machined piece out of the little tabs holding it and giving it a light sand is lots of fun.

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Muirium
µ

07 Oct 2018, 12:35

Looks delightful! You’ll have a waiting list if you get good at this!

Custom plates are a big deal. Laser cutting costs too much and has irritating MOQ. Not the friendliest thing for experiments. Besides, sometimes wood is good. I’m getting ideas!

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Laser
emacs -nw

07 Oct 2018, 16:00

Muirium wrote: Laser cutting costs too much and has irritating MOQ.
That reminded me - recently, I had a nice experience with LaserBoost; I still have to finish the keyboard (a Deltasplit75), but the plates were quite affordable, the email discussion very friendly, and there isn't a MOQ :) I think they advertised on this forum a couple of times. Despite the "Laser" name, I have no connection with them, so I'm not "advertising" to make money or something :)

andrea-i

08 Oct 2018, 09:17

I don't think it's possible to beat professional cutting services in cost and quality, but I wanted to iterate on my designs so I'm happy I've invested on a cnc of my own.

Milling the rest of this diy wooden kit is easy from here, the next challenge that will involve some learning will be milling my own PCB : )

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Muirium
µ

08 Oct 2018, 12:08

andrea-i wrote: the next challenge that will involve some learning will be milling my own PCB : )
Yes!

Lanrefni

09 Oct 2018, 18:49

Laser wrote:
Muirium wrote: Laser cutting costs too much and has irritating MOQ.
That reminded me - recently, I had a nice experience with LaserBoost; I still have to finish the keyboard (a Deltasplit75), but the plates were quite affordable, the email discussion very friendly, and there isn't a MOQ :) I think they advertised on this forum a couple of times. Despite the "Laser" name, I have no connection with them, so I'm not "advertising" to make money or something :)
I usually get my plates through Ponoko,they're not the fastest but they do have occasional sales so if your patient you can get a decent deal,currently have BFO-9000 top plates in the mail,cost $29,going to do the bottom plates out of wood and eventually middle plates out of some scrap acrylic.

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Laser
emacs -nw

10 Oct 2018, 09:54

Yes, I guess it depends a lot on our location, the LaserBoost guys are from Spain, so - closer to us Europeans :) (which means less time to wait etc.)

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